<clr-dropdown>
  <button type="button"
          class="btn btn-outline-primary btn-link"
          clrDropdownTrigger>
    实验室
    <clr-icon shape="caret down"></clr-icon>
  </button>
  <clr-dropdown-menu *clrIfOpen>
    <label class="dropdown-header">买1个</label>
    <button type="button"
            clrDropdownItem
            (click)="buy1()">买便宜的</button>
    <button type="button"
            clrDropdownItem
            (click)="buy1(false)">买更便宜的(不重复)</button>
    <div class="dropdown-divider"></div>
    <label class="dropdown-header">买最大数量</label>
    <button type="button"
            clrDropdownItem
            (click)="buyMulti()">买最大数量</button>
    <button type="button"
            clrDropdownItem
            (click)="buyMulti(false)">买最大数量 (不重复)</button>
    <button type="button"
            clrDropdownItem
            (click)="buyMultiR()">递归购买最大数量</button>
    <button type="button"
            clrDropdownItem
            (click)="buyMultiR(false)">递归购买最大数量(不重复)</button>
  </clr-dropdown-menu>
</clr-dropdown>
